Improve drawing symbols and sample popup

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

도면작성/types.ts

@@ -12,7 +12,7 @@ export type Entity = Base & (
   { kind: 'circle'; center: Point; radius: number } |
   { kind: 'hatch'; points:Point[]; holes?:Point[][];pattern:'SOLID'|'ANSI31'; spacing:number; angle:number; color?:string } |
   { kind: 'text'; point: Point; text: string; height: number; align?: 'left' | 'center' | 'right'; rotation?: number } |
-  { kind: 'dimension'; a: Point; b: Point; position: number; axis: 'x' | 'y'; height: number; value: number }
+  { kind: 'dimension'; a: Point; b: Point; position: number; axis: 'x' | 'y'; height: number; value: number; label?: string }
 );
 export type Bounds = { minX: number; minY: number; maxX: number; maxY: number };
 export type Rect = { x: number; y: number; width: number; height: number };